In 1877 the overlander, Nathaniel Buchanan and Sam Croker crossed the Barkly Tableland and rode on to the Overland Telegraph Line opening new land for settlement. It was not until the introduction of generous leasing arrangements on the Barkly in the late 1870s that the region became more settled.[3]

In 1883, Harry Readford, one of the inspirations for the literary character Captain Starlight, drove a mob of cattle to the Barkly and subsequently established Brunette Downs (then called Corella Creek), with outstations at Anthony Lagoon and Cresswell Creek, for Macdonald, Smith and Co. In 1884, 2,500 cattle were driven to Brunette Downs and in 1885, Readford brought in 1,200 mixed cattle from Burketown. Other stations in the area include Alexandria, Mittiebah and Walhallow.

Map of the region showing major roads and selected towns. The background is an elevation model so the tableland's extent can be identified as the rather uniformly coloured darker green area (corresponding to an elevation of 200–300 metres) around the appropriately named Barkly and Tableland Highways.

The Barkly Tableland rises to more than 300 metres (1,000 feet) near the Queensland and Northern Territory border. Black soil plains cover much of the Barkly Tableland.[4] Rainfall in this inland area is low (350mm pa) and subject to extreme seasonal fluctuations with rains occurring from November to March during the hot (up to 40 °C) summer. Winters are cool and frost may occur, especially in the southern section of the plain in Queensland.

The Barkly region, with a population of just over 5,900 people, has the lowest population of any region in the Northern Territory. Most live in the main towns of Tennant Creek and Renner Springs[5] Barkly has a diverse economy including agriculture, fishing, and defence but the main source of income is cattle ranching as the area includes some of the best beef cattle grazing country in Australia.

The dominant flora of the Tableland is semi-arid savanna of Mitchell grass and the area forms most of the Mitchell Grass Downs ecoregion which covers an area running 1500 km from here southeast into the Channel Country of Queensland. To the south and west of these grasslands lies the central Australian desert. The grasslands are mostly used for cattle grazing and are home to some threatened species of plants and animals. The higher areas of Mount Isa and the Selwyn Range have their own unique wildlife.

Mitchell grass is hardy with long roots so is well adapted to dry soils and periods of drought. The grasslands support other distinctive plants alongside the grasses but there are no areas of thick woodland, only acacia trees scattered across the plain.

The habitat of the Mitchell Grass Downs is mostly a uniform cover of grassland and therefore does not support a great variety of wildlife.[6] The few mammals include the brushtail possum (Trichosurus vulpecula) and the Alexandria false antechinus (Pseudantechinus mimulus), a small carnivorous marsupial found only in a number of small, isolated localities in northern Australia, including Alexandria Station on the Barkly Tableland. Meanwhile, the section of the Mitchell grasslands in Queensland is home to another endangered marsupial, the Julia Creek dunnart.

Some of the grassland is protected but most is pasture and although largely unspoilt, it is vulnerable to overgrazing, particularly areas of Queensland bluebush (Chenopodium auricomum). The downs are home to a number of endangered species and localised habitats that are threatened.